The first thing you notice about Clouds of Sils Maria is that it looks different. There’s a sense of urgency here that’s not even close to being justified by the narrative – well, in the sense that there is a narrative; this being one of those rare, refreshing films for which it can be said, for decent stretches of its running time, “nothing happens” – and it’s an urgency that can be located most obviously in its transitions and in its occasional bouts of double exposure.

But it doesn’t just look different; it feels different, too. This is about as close as French arthouse cinema gets to the style of Eric Rohmer nowadays, in that the characters keep talking when there is no expository purpose. But that just seems all the more fitting in a film about acting – a profession that, after all, can be boiled down to saying words.

From way back in the ‘90s, with Maggie Cheung’s meta-role in Irma Vep, Olivier Assayas has shown an interest in performance as a narrative concern. In Clouds of Sils Maria, Juliette Binoche’s character is nearly always acting – reading lines, because that’s her job, or engaging in repartee with her more down-to-earth personal assistant.

For all of Binoche’s gravitas, it’s the latter role, Kristen Stewart’s, that really anchors the film (which, spoiler alert, makes it all the more jarring when she disappears without explanation or comment). There’s a naturalism to her sidekick role that stands in direct contrast to her boss’s theatrical antics, and that really comes to the fore when we’re confronted with the paradox of Stewart, an actor, playing a non-actor reading another actor’s lines. And if she’s just been a figment of Binoche’s imagination all along, as Assayas teases us, she would have to be the most delightfully mundane imaginary friend anyone could wish for.

Because Binoche is middle-aged now, and because middle-aged women aren’t allowed to be in films, this is a “film about ageing”. Her character, we learn, has been given a role as the older lover in a decades-later remake of a theatrical production in which she once played the other role, the young woman. This play-within-a-film doesn’t seem terribly interesting – something about a manipulative relationship in an office environment – and its dialogue is risible, but that’s not really the point. Or, at least, the film is strongest when it’s most clearly not the point, because one can only endure so much back-story about a fake director’s misunderstood genius.

Less interesting, too, are the film’s observations about generational change; the final act slipping dangerously into “I just don’t know what’s wrong with the youth of today” territory. In that respect, Clouds of Sils Maria is almost a companion piece to Noah Baumbach’s While We’re Young (Brady Corbet even shows up!) and that’s not a comparison I expect Assayas would be enthusiastic about. But if these flaws are overlooked, Clouds of Sils Maria can be enjoyed as an intellectually engaging and defiantly unique film – in 2014, no mean feat.